Wireless transmission system



June 1 1926. 1,586,653

- F. CONRAD WIRELESS TRANSMISSION SYSTEM Filed March 10. 1922 F/yfi. 8

I4 I L /a 22 =5 WITNVES INVENTOR W fiv/lkfmmaf TTORNEY;

Patented June 1, 1926.

UNITED STATES ,a TENT OFFICE.

IBANK CONRAD, or" r r'rsnunon," PENNSYLVANIA, ASSIGNOR mo wnsr NGHousa ELECTRIC a MANUFACTURING COMPANY, A CORPORATION or PENNSYLVANIA.

Q WIRELESS f TRANSMISSION SYSTEM.

A u aaonfniea March 10, 1922. Serial No. 542,690.

portant disadvantage of the type of antenna just mentioned is the large resistance losses caused by the heavy charging currents supplying'the extreme portions of the antenna. Another important disadvantage of such high-power antenna systems arises from the fact that their high apparent resistance renders them unsuited for the employment of to coils 15 which are inductively associated arc oscillators of usual construction.

An object of my invention, therefore, is,

toprovidemeans whereby an are system may beemployed'in'connecti'on with a plurality includes an arc17 connected in circuit beof multiple-tuned antennae.

Another object of my invention is to provide means for varying the apparent resistance of a group of multiple-tuned anten-' nae whereby the antenna-system may be adjusted to the critical resistance required'for maximum efiiciency in connection with an .arc oscillator.

Other objects, as wellras the details of construction, whereby my invention may be carried out, will be apparent vfromthe following description and claims when read in connection with ings, wherein,

Figure 1 i's'a diagrammatic perspective view of circuits and apparatus embodying my invention, and.

Figs. 2 and'3 are similar views. illustrating alternative arrangements.

According to my'inve'ntion,I provide an antenna system comprising a group of preferably small,"insulated, non-parallel anten- I nae, each havingaiseparateground connec- Fig. 3 shows a square arrangement employthe accompanying draw-' tion and tuning coil, In Fig. 1, I have illustrated the antenna system as comprising a ing four separate antennae 5, 6, 7, and,8., The

- ground'connections and tuning coils. are indicated, respectively, at.9 and 10. The an-. tennae may be insulated one from'another by insulators 11 which may be carried by towers12. t I

If any one of the antennae circuits, such as ground connection 9, is set in oscillation, and

' the other antennae are tuned to the same fre-- :quency, oscillations may be induced in the last mentioned antennae by means of conductors connecting any point of the first oscillating system, having a potential different from ground potential, to a corresponding point in each of the other circuits. The inthe antenna 5, and its tuning coil 10 and I terconnections between the various circuits 13 connecting intermediate "taps 14 on the tuning coils 10, asillustrated in Figs- 1 and- 2. In the modification shown in Fig. 3, the interconnecting conductors 13 are connected with the respective tuning coils 10. I have shown an arc oscillator 16jas a source of oscillating currents. Theoscillator tween the tuning coil and ground connection '9 of the antennae; The are may be energized by means of a direct-current generator 18 connected thereto through choking coils 19, and the oscillations may be modulated by supplies the various'losses, such as ohmic and radiation losses, and a large wattless component. A

The oscillating current will' be composed of a small component, that may becalled the power component, which maybe easily made'by means of'conductors I When the interconnecting conductors 13 i are connected to thetaps 14 ofthe yarious tuning coils, it willbenecessary for small currents to traverse the interconnecting con ductors in order to supplythe losses in the antennae which are not directly connected to the arc oscillator. It is apparent, however, that the currents flowing in the conductors 13 becomelarger as the tap points 14 are moved downward, thereby decreasing the potential. Hence, the total current flowing through the are 17 becomes larger as the tap stant, thus producing an effect of decreasing the resistance of the oscillating circuits connected to said arc.

In my copending application, Serial No.

430,630, filed December I l, 1920, I have disclosed a similar antenna system in which the are oscillator 16 is omitted and a source of oscillations is connected between the interconnecting conductor 13 and the ground. With this connection, the source of oscillation is traversed only by the energy components of the oscillating currents, whereas, in the present application, as above pointed out, the are 17 carries a current in excess of the total oscillating current in the antenna 5. Since it is necessary that the are of an arc oscillator shall be shunted by a tuned oscillating circuit, the direct inclusion of the arc in circuit with one of the antennae ground connect-ions, as illustrated in the present application, is desirable in that it avoids the necessity for the employment of separate tuning condensers in the arc circuit, which would be necessary if the are were connected as shown in my copending application.

In the arrangement shown in the present application, it is understood, of course, that stopping condensers 20 will be provided for preventing the short-circuiting of the directcurrent source 18. In Fig. 1, a single stopping condenser 20 is shown in the ground connection of antenna 5 between the tuning coil 10 and the ground 9. In Fig. 2, a stepping condenser 21 is placed in each of the interconnecting conductors 13. In Fi 3, a stopping condenser 22 is placed in the ground connect-ion of each of the antenna: 6, 7 and 8.

By disposing the tuning coils or powertransformers directly beneath the antennae, I am enabled to energize the several anten nae at relatively low voltages which, in an are system, is a decided advantage. A further advantage of this system of distribution is that the usual corona losses in the conductors extending from the source of power to the antenna are reduced to a minimum.

Another advantage is the provision of a radiating system in which the phase displacement of the waves radiated by the sev eral antenna (with respect to each other) is substantially zero.

The particular advantage of my invention, however, is in the provision of means whereby a plurality of antennae may be ener gized from a single arc-converter system, which may or may not be included directly in one of the antenna ground-leads.

lVhile I have shown three embodiments of my invention, it is obvious, to one skilled in the art, that various modifications may be made both in the arrangement of the antenna and in the disposition of the stopping condensers without departing from the spirit and scope of my invention. I desire, therefore, that only such limitations shall be imposed thereon as are indicated in the appended claims.

I claim as my invention:

'1. In a wireless transmission system, the combination with a. plurality of antenna circuits tuned to the same frequency, of a source of oscillations included in one of said circuits, and connections between points having like potentials in the several circuits, wherebyall of said circuits are caused to oscillate in unison.

2. In a wireless transmission system, the combination with a plurality of antenna circuits tuned to the same frequency, of an arc oscillator included in one of said circuits, and connections between points having like potentials in the several circuits, whereby all of said circuits are caused to oscillate in unison.

3. In a wireless sending station, the combination with a main oscillating circuit, of a second oscillating circuit, a source at said station of oscillations for said first-mentioned circuit, and a conductor connecting points of like potential in the respective circuits, said connecting points being adjustable, whereby the apparent resistance of said second oscillating circuit may be varied.

4. In a wireless signaling system, the combination with a plurality of non-paralle1 antennae and an arc-converter system, of separate tuning means for each antenna and means whereby each antenna may be energized from said arc-converter system.

5. In a wireless signaling system, a plurality of non-parallel antennae, a groundlead for each antenna, means included in each ground-lead whereby each antenna may be separately tuned, an arc-converter system and means whereby each antenna may be energized from said arc-converter system.

6. In a wireless signaling system, a plurality of antennae so grouped about a central point that the greatest distance between two antenna ends is less than the sum of the distances between the ends of the several antennae, a ground lead for each antenna, means included in each ground lead whereby each antenna may be separately tuned, a single arc-converter system and means whereby said plurality of antenna: may be energized from said arc-converter system.

7. In a wireless signaling system, a plurality of antennae so grouped about a central point that the greatest distance between two antenna ends is less than the sum of the distances between the ends of the several antennae, a ground-lead for each antenna, a tuning coil for each antenna, a single source of energy, and means including said tuning coils for energizing all of said antenna, from saidsource.

8. A wireless signalinlg system comprising a plurality of non-parallel radiating antennae systems, each antenna system be.-

ing tuned to substantially the same fre quency, an arc converter included in one of said antennae systems and means for operatively connecting the remaining antennae systems to said arc-converter, said means ineluding means for preventing the flow of direct current. i v v 9. In a Wireless signaling system, a plurality of radiating antennae, a plurality of towers for supporting said antennae, said antennae extending radially outwardly from one of said supporting towers, a

ground-lead circuitifor each antenna and including therein an inductance coil, an arcplurality of non-parallel antennae, a groundlead for each antenna, means included in each ground-lead whereby each antenna may be separately tuned, a single arc-converter system and means whereby each antenna may be energized from" said arc-converter system. I r

In testimony whereof, I have hereunto subscribed my name this 4th day of March, 1922. I

FRANK CONRAD. 

